Making The Most Making The Most of Continuous Glucose of Continuous Glucose MonitoringMonitoring

Gary Scheiner MS, CDEOwner/Director, Integrated Diabetes Services333 E. Lancaster Ave., Suite 204Wynnewood, PA 19096(877) 735-3648www.integrateddiabetes.comGary@integrateddiabetes.com

Making the Most of Continuous Glucose Monitoring

1. What Information Is Available?

2. How to Use Immediate Data?

3. How to Use Intermediate Data?

4. What Can Be Learned from Retrospective Analysis?

5. Optimizing CGM System Performance

MiniMed Paradigm® & Guardian® REAL-Time CGM Systems

On-Screen Reports

• 3-hr and 24-hr graphs (pump); 3 / 6 / 12 / 24-hr graphs (Guardian)

• Can scroll back for specific data points

• “direction” indicators• Updates every 5 minutes• Hi/Low Alerts• Predictive Alerts (Guardian)

CareLink™ Personal:Online Reports

• Sensor daily overlay

• Sensor overlay by meal

MiniMed Paradigm® & Guardian® REAL-Time CGM Systems

Daily summaries & layered reports, including…

• Sensor tracing

• Basal & bolus delivery

• Carbohydrate & logbook entries

MiniMed Paradigm® & Guardian® REAL-Time CGM Systems

CareLink™ Personal Online Reports

DexCom™ 7 STS®

On-Screen Reports

• 1, 3, 9-hr graphs

• Updates every 5 minutes

• Hi/Low alerts

DexCom™ 7 STS®

Hourly Stats Glucose Trend

Dexcom DM2 Download Reports

DexCom™ 7 STS®

BG Distribution

Trend Analysis

Dexcom DM2 Download Reports

Freestyle Navigator™

On-Screen Reports

• 2/4/6/12/24-hr line graphs• Predictive alerts• “direction”

indicators• Can scroll back to data points

• Customizable time range: • Highest, Lowest, Avg, SD• % Time High, Low, In-Range• # Hypo, Hyper events

• Updates every minute

Practical Benefits of Real-Time CGM• Rumble strips (avoid serious extremes)

• Peace of mind

• Basal & bolus fine tuning

• Postprandial analysis

• Insulin action curve determination

• Short-term Forecasting

• Learning tool & immediate feedback

• Eliminates some blood glucose checks???

Partially derived from: Hirsch, et al. Clinical Application of Emerging Sensor Technologies in Diabetes Management: Consensus Guidelines for Continuous Glucose Monitoring (CGM). Diabetes Technology & Therapeutics, 10:4, 2008, 232-244.

How to Look at the Information

• Immediate

• Intermediate

• Retrospective

                                          

      

Immediate Info: Alerts

• Alert the user of glucose levels that have crossed specified thresholds, either high or low

• Visual cues on-screen

• Vibrations, audible tones

Setting Alerts

• Individualize settings

• Alarm thresholds are not BG targets

• Balance need for alerts against “nuisance factor”

LOW: 80 mg/dl(90+ if hypo unaware)

HIGH: 240 mg/dL(lower progressively toward 180)

NOT RECOMMENDED: Low 70 mg/dL NOT RECOMMENDED: High 140 mg/dL

Alert Settings Recommendation

Derived from: Hirsch, et al. Clinical Application of Emerging Sensor Technologies in Diabetes Management: Consensus Guidelines for Continuous Glucose Monitoring (CGM). Diabetes Technology & Therapeutics, 10:4, 2008, 232-244.

Special Alert Settings

• Young children (higher, wider range)

• Hypoglycemia unawareness (higher)

• Pregnancy (lower, narrower range)

• HbA1c of 11.0% (higher initially)

Immediate Info: Real-Time Adjustments

• Prediction/Forecasting

• Safety/Performance•Driving• Sports• Tests

Immediate Info: Real-Time Adjustments

• Replace Fingersticks?• Not during first 3-7 days of

system use

• Wait until 12-24 hrs after sensor replacement

• If BG Stable

• If Recent calibrations in-line

• If No recent alarms

Immediate Info: Potential Bolus Adjustment

Based on BG Direction• BG Stable:

Usual Bolus Dose

• BG Rising Gradually: bolus 10%

• BG Rising Sharply: bolus 20%

• BG Dropping Gradually: bolus 10%

• BG Dropping Sharply: bolus 20%

Immediate Info: Hypoglycemia Alerts

• Predictive Hypo Alert: Subtle Treatment • 50% of usual carbs

•Med-High G.I. food

• Hypo Alert & Dropping: Aggressive Treatment• Full or increased carbs

•High G.I. food

Intermediate Info:Use of 2/3/4 Hr Trend Graphs

• Effects of different food types

• Effectiveness of bolus amt.

• Reveals postprandial spikes

• Pramlintide/Exenatide Influence

• Exercise effects

• Impact of Stress

Intermediate Info:Use of 9 / 12 / 24 Hr Trend Graphs

• Facilitates decision-making for basal insulin doses

• Shows delayed effects of exercise, stress, high-fat foods

• Reveals overnight patterns

• Lets user know when bolus action is complete

Specific Insights to Derive(a purely retrospective journey)

Case Study 1: Effectiveness of Current Program

• Type 1 diabetes; using insulin glargine & MDI• Overnight readings are OK; HbA1c levels are elevated

Meal doses insufficient; not covering snacks?Meal doses insufficient; not covering snacks?

3 AM 6 AM

Glu

cose

(m

g/d

L)

400

300

200

100

0

9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 2a: Basal Insulin Regulation

• Rising 2 AM – 8 AM• Rising 2 AM – 8 AM• Stable 12 AM – 4 AM, then dropping pre-dawn

• Dropping late afternoon

• Stable 12 AM – 4 AM, then dropping pre-dawn

• Dropping late afternoon

3 AM 9 AM 3 PM 9 PM 3 AM 9 AM 3 PM 9 PM

Glu

cose

(m

g/d

L)

400

300

200

100

0

400

300

200

100

0

Case Study 2b: Basal Insulin Regulation

• Type 1 diabetes; using insulin glargine & MDI• History of morning lows• Now not “covering” highs at night

BG dropping overnight; insulin dose too highBG dropping overnight; insulin dose too high

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 3: Detection of Silent Hypoglycemia

• Type1 diabetes; on pump

• Frequent fasting highs (9 AM)

Somogyi effect during the nightSomogyi effect during the night

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 4: Determination of Insulin Action Curve

3-Hour Duration

5-HourDuration

4-Hour Duration

Case Study 5: Fine-Tuning Meal Boluses

Breakfast and lunch doses

may be too low

Breakfast and lunch doses

may be too low

Dinner dose appears OK Dinner dose appears OK

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM

Night-snack dose clearly insufficient

Night-snack dose clearly insufficient

Case Study 6: Fine-Tuning Correction Boluses

Need to change correction factor & insulin sensitivity during AM hours

Need to change correction factor & insulin sensitivity during AM hours

• Dropping low after correcting for highs at bedtime and wake-up time

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 7: Postprandial Analysis

• Pre-meal BG levels are usually in target range• HbA1c are higher than expected based on SMBG• Tired and lethargic after meals

Significant postprandial spikes (300s)Significant postprandial spikes (300s)

Glu

cose

(m

g/d

L)

400

300

200

100

Meal

Meal

MealMeal

Case Study 8: Impact of Physical Activity

• Type 1 diabetes; pump user• Basal rates confirmed overnight• Exercises in the evening (9 PM)

Experiencing delayed-onset hypoglycemiaExperiencing delayed-onset hypoglycemia

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 PM 6 PM 9 PM 12 AM 3 AM 6 AM 9 AM 12 PM

Exercise

Case Study 9: Impact of Stress

• Type 1 diabetes; pump user

• 40 years old; athletic

• Handsome, excellent speaker

• Gets flat tire; eats 15g carbs to prepare for tire change

• Spare is flat too!!

STRESS CAN RAISE BLOOD GLUCOSE… A LOT!!!STRESS CAN RAISE BLOOD GLUCOSE… A LOT!!!

• Late for meetingG

luco

se

(mg

/dL

)

400

300

200

100

0

9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 10: Impact of Various Food Types

BG peaks later with pasta than rice

BG peaks later with pasta than rice

Postprandial peak: cereal > oatmeal > yogurtPostprandial peak:

cereal > oatmeal > yogurt

Pasta MealStir-Fry Over Rice

CerealOatmealYogurt

Optimizing CGM System Performance

• Calibration

• Site selection/care

• Signal reception

• Ingredients for success

• Calibrate at times when blood glucose (BG) is stable (fasting, pre-meals)

• Avoid calibrations during times of rapid glucose change– Post meal

– UP or DOWN arrows are displayed

– In the period following a correction with food or insulin

– During exercise

Optimal Calibration

• Calibrate before bedtime to avoid alarms during the night

• Use good technique when performing BG checks for calibration– Proper coding

– Clean hands

• USE FINGERSTICKS

• Enter the calibration immediately after the fingerstick (Dexcom, Medtronic systems)

Optimal Calibration

Sensor Sites• Site Selection

– “Fleshy” areas

– At least 3” Away from insulin infusion

– Avoid tight clothing areas, scars, bruises, lipoatrophy

– Rotate sites

• Bleeding/Irritation– Slight bleeding OK

– Profuse bleeding: remove

– Remove introducer needle at proper angle

Sensor Sites• Adhesive

– Completely cover the Transmitter & Sensor (Navigator & Medtronic systems)

– Check sensor daily for loose tape– Apply extra tape over sensor & transmitter if tape patch begins to

“curl” around edges

• Site Irritation– Watch for redness, swelling, tenderness– Remove sensor with prolonged irritation (>1 hour)

Signal Reception• Heed transmitter ranges

– Medtronic: 6 ft.– Dexcom: 5 ft.– Navigator: 10 ft.

• Signals do not travel well through water

– Wear receiver on same side of body as sensor

• Keep receiver very close while charging (Dexcom)

• Charge transmitter fully every 6 days (Medtronic)

            

       

Ingredients For Success

• Wear the CGM at least 90% of the time

• Look at the monitor 10-20 times per day

• Do not over-react to the data

• Adjust your therapy based on trends/patterns

• Take IOB into account when using CGM values

• Minimize “nuisance” alarms

Source: Dr. Bruce Bode, personal observation.

Think Like A Pancreas!